This invention relates to inflatable structures for treatment of hypothermia, and is used in a medical setting to deliver a bath of a thermally-controlled medium to a patient. In particular, the thermally-controlled medium is used to inflate the structure and is expelled therefrom onto a patient. Still more particularly, the invention relates to inflatable structures for the treatment of hypothermia in infants and small children.
The relevant art is perhaps best expressed in U.S. Pat. No. 4,572,188 entitled "AIRFLOW COVER FOR CONTROLLING BODY TEMPERATURE," and commonly assigned with this application. In the prior patent, a self-erecting, inflatable airflow cover is inflated by the introduction into the cover of a thermally-controlled inflating medium, such as warmed air. When inflated, the cover self-erects about a patient, thereby creating an ambient environment about the patient, the thermal characteristics of which are determined by the temperature of the inflating medium. Holes on the underside of the prior art airflow cover exhaust the thermally-controlled, inflating medium from inside the cover to the interior of the erected structure. The airflow cover is intended for the treatment of hypothermia, as might occur operatively or postoperatively.
An alternative embodiment airflow device in the '188 patent includes an inflatable, annular tube which fits to a patient's head. Air holes are provided in the tube, as is an entry port. A sheet of material attached to one side of the annular tube retains a warmed inflating medium within a circular space that contains the top of a patient's head. An exit port is cut in the sheet to exhaust the inflating medium from within the structure.
Evaluation of the airflow cover described in the '188 patent by skilled practitioners has resulted in general approbation: the opinion is that the airflow cover efficiently and effectively accomplishes its purpose of giving a thermally-controlled bath. However, since the airflow cover extends unbrokenly from the feet to the neck of a patient, it cannot be used in the operating room during surgery. In order to accommodate the essential structure of the airflow cover to use during surgery on clinical treatment, we have developed airflow covers suitable for thermal treatment of portions of the body during surgery. In particular, inflatable thermal blankets for covering particular body portions while surgery is conducted on non-covered portions are described and illustrated in the cross-referenced U.S. patent application Ser. No. 07/638,748.
The positive result obtained from use of the airflow cover and body portion thermal blankets notwithstanding, thermal maintenance of pediatrics patients during and after surgery presents a new challenge. Particularly, such a patient must receive a supply of heated air which is adequate for thermal treatment, which is appropriate to the size of the patient, and which provides access to a care site. In particular, we have realized that a need exists for an inflatable apparatus for thermally treating infants and small children both operatively and postoperatively.